1. Field of the Invention
The present invention relates to an abnormal condition detector of an electric apparatus in which an insulating gas is filled, such as gas insulating switch.
2. Description of the Prior Arts
In general, reactive acidic gases such as SF.sub.4 and HF are produced as decomposed components in an electric apparatus containing SF.sub.6 gas such as a gas insulating switch and acidic gases such as NO.sub.2 are produced as decomposed components in an electric apparatus containing air and acidic gases such as HF are produced as decomposed components in an electric apparatus containing freon gas.
These acidic gases cause a corrosion of the electric apparatus to shorten the life of the electric apparatus. Accordingly it is desired to detect the formation of the acidic gases that is the abnormal condition in early stage.
In general, when a fault is caused in an electric apparatus, the decomposed gases are produced whereby a commercial gas detector can be used as a fault detector.
However, such gas detector is mainly used for detecting a low concentration level and it responds to only one object component and it is not clearly understood whether suitable detection can be performed when various decomposed gases are produced in the electric apparatus and they are gradually produced.
FIGS. 1 and 2 show sectional views of the conventional gas detectors used for the fault detection.
In FIGS. 1 and 2, the numeral reference (1) designates a detecting tube through which a measured gas is passed; (11) designates a detecting material being inductive with a specific component contained in the measured gas and the detecting material is contained in the detecting tube (1); (2) designates a sucking means for passing the measured gas through the detecting tube (1). In the embodiment of FIG. 1, a cylinder is used as the sucking means and in the embodiment of FIG. 2, a rubber bellows is used as the sucking means. The reference numeral (21) designates means for detachably connecting the detecting tube (1) to the sucking means (2). In FIG. 2, the reference numerals (22), (23) designate a pair of switch valves for pumping function.
In the gas detector having the above-mentioned structure, one end of the detecting tube (1) is disposed to the measured gas under the atmospheric pressure and a specific amount of the measured gas is sucked by the sucking means (2) and a specific component such as SO.sub.2, CO, NO.sub.2 gas is analyzed by qualitative or quantative analysis depending upon the kind of the detecting material (11) and the coloring range of the detecting material.
However, in the conventional apparatus or the conventional method of detecting the abnormal condition of the electric apparatus by the gas detector measuring the acidic gases produced by certain fault in the electric apparatus such as a gas insulating switch, the electric apparatus containing a fluid such as the gas insulating switch is under pressurized condition, whereby it is necessary to reduce the pressure by a pressure control valve and also to use a chamber for storing the measured gas. Moreover, it takes a long time such as one minute per one stroke. When a concentration of the measured gas is low, many strokes are disadvantageously required for the sampling disadvantageously.
The conventional apparatus has such disadvantages. In the case of an apparatus having many gas chambers such as a gas insulating substation, there is the further disadvantage of lack of speed for detecting the abnormal condition.